Hastings student Lucan Battison, who won a High Court battle to keep his long locks, got the green light to go to his school ball only hours before it started.

Lucan's dad, Troy Battison, said he hadn't seen his son since he left for the ball last night as the 16-year-old was still enjoying a sleep in this morning.

"We didn't find out he was able to go to the ball until about 3pm yesterday so it was all a bit of a rush.''

Battison was kicked out of class on May 22 after ignoring requests from St John's College to cut his hair. He offered to tie it back in a bun but this was unacceptable to the school.

Last week Justice David Collins ruled in favour of the year 12 student, saying his suspension was unlawful - as was the hair rule set out by the school.

Lucan returned to college on Wednesday after Collins, during Monday's hearing, asked the school to take him back pending his decision and without interim punishment.

But the school put its foot down and told Lucan he wouldn't be attending the school ball.

Other activities outside the classroom had also been restricted, after Lucan showed up with his boots for first XV rugby practice earlier this week only to be told he couldn't train.

Lucan and his parents said they were pleased with the judgment but disappointed it had to go to the High Court. "Our preferred option all along was mediation."

While rules had a place, they needed to be "reasonable and certain", they said."Lucan never broke the rules. The rules which we signed up for, were 'off the collar and out of the eyes'. Lucan's hair, whether in a hair-tie or not, has conformed to this, but the new principal shifted the goal posts."

In this case it was the school that did not follow the law, they said. "If people never questioned certain issues, we would be a very backward society today."